The present invention relates generally to systems which control the pointing of mechanical structures such as radar antennas and beam steering mirrors, and more specifically to a digitally controlled servomechanism.
In the world of mount control technology, it is a well known fact that controlling massive structures to a few microradians requires special compensation. Until now, the requirement to position mounts to this precision has forced the rate feedback, mount dynamics compensation, and error correction control to be performed with analog technology. Although analog servos do indeed perform well, their limitations are also well known. Frequent adjustments of their designs are necessary to maintain precision of operation. These adjustments are extremely time-consuming since the design is implemented in circuitry.
Mount control systems have successfully used analog servo systems as the primary means of control because of their proven ability to position the mount with microradian precision. Since the invention of the computer, many have also tried (unsuccessfully) to transfer this analog task to the computer. While digital filter technology has been available for quite a long time, computer technology has only recently become cost effective and capable enough to make digital filters an economic alternative to analog filters.
The task of implementing digital filter technology to digitally control servomechanisms is alleviated, to some extent, by the systems disclosed in the following U.S. Patents, the disclosures of which are incorporated herein by reference:
U.S. Pat. No. 4,950,063 issued to Pohle et al.